Tyrian purple


For more on Tyrian purple see the article Indigo and Tyrian Purple—In Nature and in the Lab in the November 2001 issue of the Journal of Chemical Educa tion pp 1442-1443  [c.4]

Textile dyes were, until the nineteenth century invention of aniline dyes, derived from biological sources plants or animals, eg, insects or, as in the case of the highly prized classical dyestuff Tyrian purple, a shellfish. Some of these natural dyes are so-caUed vat dyes, eg, indigo and Tyrian purple, in which a chemical modification after binding to the fiber results in the intended color. Some others are direct dyes, eg, walnut sheU and safflower, that can be apphed directly to the fiber. The majority, however, are mordant dyes a metal salt precipitated onto the fiber facUitates the binding of the dyestuff Aluminum, iron, and tin salts ate the most common historical mordants. The color of the dyed textile depends on the mordant used for example, cochineal is crimson when mordanted with aluminum, purple with iron, and scarlet with tin (see Dyes AND DYE INTERMEDIATES).  [c.423]

Another ancient dye is the deep blue indigo [482-89-3], the presence of two bromine atoms at positions gives the dye Tyrian purple [19201 -53-7] once laboriously extracted from certain sea shells and worn by Roman emperors.  [c.419]

Indigoid dyes represent one of the oldest known classes of dyes. For example, 6,6 -dibromoindigo [19201 -53-7] (44) is Tyrian Purple, the dye made famous by the Romans. Tyrian Purple was so expensive that only the very wealthy were able to afford garments dyed with it. Indeed, the phrase "bom to the purple" is still used today to denote wealth.  [c.280]

The solution at this point should be clear, but it may acquire a rather pronounced orange-yellow color when viewed in bulk. It should not, however, turn purple.  [c.70]

For more on Tyrian purple, see the article "Indigo and Tyrian Purple—In Nature and in the Lab" in the November 2001 issue of the Journal of Chemical Education, pp. 1442-1443.  [c.4]

Figure 8.24 (a) Structure of the CAP-cyclic AMP-DNA complex. The two protein chains of the dimeric CAP molecule are colored green and brown. The helix-turn-hellx motif is blue and red with the recognition helix and the C-terminus red. The DNA which is kinked where the recognition helices bind is orange and the cyclic AMP molecules are purple, (b) Schematic diagram of the structure of one subunit of CAP. The p strands (1-12) and a helices (A-F) are labeled from the N-terminus. The DNA-binding helix-turn-helix motif is colored blue and red with the recognition helix red. The binding site for cyclic AMP is purple, [(a) Adapted from S.C. Schultz et al.. Science 2S3 1001-1007, 1991. (b) Adapted from D. McKay and T. Steitz, Nature 290 744-749, 1981.]  [c.146]

Figure 10.10 Structure of the complex between the dimeric glucocorticoid receptor molecule and a DNA fragment (orange). The two zinc-binding regions of each subunit have different colors brown and dark green in one subunit and red and light green in the second. The linker region is blue. The recognition helices of the dimer (red and brown) are positioned In the major groove. The distance between them, which corresponds to one turn of the DNA helix. Is fixed by the dimerization loop (purple). This region undergoes a significant conformational change when the dimer binds to DNA. (Adapted from B.F. Luisi et al.. Nature 352 497-505, 1991.) Figure 10.10 Structure of the complex between the dimeric glucocorticoid receptor molecule and a DNA fragment (orange). The two zinc-binding regions of each subunit have different colors brown and dark green in one subunit and red and light green in the second. The linker region is blue. The recognition helices of the dimer (red and brown) are positioned In the major groove. The distance between them, which corresponds to one turn of the DNA helix. Is fixed by the dimerization loop (purple). This region undergoes a significant conformational change when the dimer binds to DNA. (Adapted from B.F. Luisi et al.. Nature 352 497-505, 1991.)
In the photosynthetic membrane there is a downhill flow of energy from the light-harvesting proteins to the reaction centers. In purple bacteria, LH2 absorbs radiation at a shorter wavelength (higher energy) than LHl and therefore delivers it to LHl, which in turn passes it on to the reaction center. A photon that is absorbed by the 800-nm chlorophylls in LH2 is rapidly transmitted to the energetically lower periplasmic ring of 850-nm chlorophyll in the same complex. Spectroscopic measurements have shown that the energy absorbed by a chlorophyll in the periplasmic rings spreads to the others, within 0.2 to 0.3 picoseconds. When a photon is absorbed by any of these chlorophylls it becomes in effect delocalized between the chlorophyll molecules of the ring. It can then easily jump to another chlorophyll in an adjacent complex, where it again becomes delocalized until it ends up at the reaction center, as schematically illustrated in Figure 12.22.  [c.243]

Colourless crystals, m.p. I64 C. A base found in ergot, and in putrefying animal and vegetable material and certain cheeses where it is formed by bacterial action on tyrosine. It is usually made synthetically and has a weak and prolonged pressor action, caused by its ability to release noradrenaline from sympathetic nerve endings and from.the adrenal medulla, tyrian purple, CifiHgBriNjOi. A purple vat dye of great antiquity. Occurs in the shell fish Murex brandaris from which it was once extracted for making royal purple.  [c.410]

As early as 2500 bce m India indigo was used to dye cloth a deep blue The early Phoenicians discovered that a purple dye of great value Tyrian purple could be extracted from a Mediterranean sea snail The beauty of the color and its scarcity made purple the color of royalty The availability of dyestuffs underwent an abrupt change m 1856 when William Henry Perkin an 18 year old student accidentally discovered a simple way to prepare a deep purple dye which he called mauveme from extracts of coal tar This led to a search for other synthetic dyes and forged a permanent link between industry and chemical research  [c.4]

Initially ah. coloring matters were of natural origin obtained from plants and even animals. Woad and indigo (violet), madder (red), and weld (yeUow) were typical of coloring matters extracted from plants. Coloring matters obtained from animals included Tyrian Purple from a species of whelk and the reds cochineal and kermes from insects. The actual colors used would depend on geographical avahabhity. In one area the coloring matters would not necessarily be the same as other areas. As the number of available coloring matters increased, either by discovery, improved communications, or trading, it became possible to be selective. Compounds with poorer properties were no longer used. For example the use of kermes in Europe, which was available locally, declined in favor of first lac (from India), and then cochineal from India and the Americas as a result of the improved brightness and color strength of the latter compounds. By the time of the Renaissance, coloring matters derived from safflower and Bra2ilwood were available. Gradually the range of dyes available increased but always from natural sources (see Dyes, natural).  [c.348]

There are a number of myths relating to the discovery of Tyrian Purple. One such goes as follows a Tyrian god was walking along the shore accompanied by his dog and a nymph. Suddenly the dog bit iato a shellfish, whereupon his mouth became stained a beautiful purple. Seeiag this, the nymph begged the god to have a dress made for her dyed with this new dye. He granted her wish and won her everlasting favor.  [c.401]

As early as 2500 bce in India, indigo was used to dye cloth a deep blue. The early Phoenicians discovered that a purple dye of great value, Tyrian purple, could be extracted from a Meditenanean sea snail. The beauty of the color and its scarcity made purple the color of royalty. The availability of dyestuffs underwent an abr-upt change in 1856 when Williffln Henry Perkin, an 18-year-old student, accidentally discovered a simple way to prepare a deep-purple dye, which he called mauveine, from extracts of coal tar-. This led to a search for other synthetic dyes and forged a permanent link between industr-y and chemical research.  [c.4]

P. Friedlander showed that Tyrian Purple from Murex brandaris was 6,6 -dibromoindigo (previously  [c.791]

The magnificent purple pigment referred to in the Bible and known to the Romans as Tyrian purple after the Phoenician port of Tyre (Lebanon), was shown by P. Friedlander in 1909 to be 6,6 -dibromoindigo. This precious dye was extracted in the early days from the small purple snail Murex brandaris, as many as 12000 snails being required to prepare 1.5 g of dye. The element itself was isolated by A.-J. Balard in 1826 from the mother liquors remaining after the crystallization of sodium chloride and sulfate from the waters of the Montpellier salt marshes  [c.793]

Bis(cyclopentadienyldicarbonyliron) [12154-95-9] [Fe(CO)2(C H )]2, is a purple-red, air-sensitive soHd. It is frequendy designated Fp2 where Fp is an abbreviation for (C H )Fe(CO)2. The compound is prepared by reacting Fe(CO) and dicyclopentadiene at 135°C ia an autoclave. Strong reduciag agents cleave Fp2 to Fp ia polar aprotic solvents. The anion can be alkylated to afford (C H )Fe(CO)2R complexes, which ia turn react with hydride abstracting reagents to afford cationic (C H )Fe(CO)2(olefiQ) complexes. Both of these mononuclear compounds have considerable utility ia organic syntheses (12,14).  [c.441]

Aminophenol. This compound forms white plates when crystallized from water. The base is difficult to maintain in the free state and deteriorates rapidly under the influence of air to pink-purple oxidation products. The crystals exist in two forms. The a-form (from alcohol, water, or ethyl acetate) is the more stable and has an orthorhombic pyramidal stmcture containing four molecules per unit cell. It has a density of 1.290 g/cm (1.305 also quoted). The less stable P-form (from acetone) exists as acicular crystals that turn into the a-form on standing they are orthorhombic bipyramidal or pyramidal and have a hexamolecular unit (15,16,24) (see Tables 3—5).  [c.309]

The use of an acidic solution of p-anisaldehyde in ethanol to detect aldehyde functionalities on polystyrene polymer supports has been reported (beads are treated with a freshly made solution of p-anisaldehyde (2.55 mL), ethanol (88 mL), sulfuric acid (9 mL), acetic acid (1 mL) and heated at 110°C for 4 min). The colour of the beads depends on the percentage of CHO content such that at 0% of CHO groups, the beads are colourless, -50% CHO content, the beads appear red and at 98% CHO the beads appear burgundy [Vdzquez and Albericio Tetrahedron Lett 42 6691 200]]. A different approach utilises 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole (Purpald) as the visualizing agent for CHO groups. Resins containing aldehyde functionalities turn dark brown to purple after a 5 min reaction followed by a 10 minute air oxidation [Coumoyer et al. J Comb Chem 4 120 2002].  [c.76]

FIGURE 6.4 A Ratnachandran diagram showing the sterically reasonable values of the angles (/> and fp. The shaded regions indicate particularly favorable values of these angles. Dots in purple indicate actual angles measured for 1000 residues (excluding glycine, for which a wider range of angles is permitted) in eight proteins. The lines running across the diagram (numbered -H5 through 2 and —5 through —3) signify the number of amino acid residues per turn of the helix T means right-handed helices means left-handed helices. (After Richardson, J.. S., 1981, Advances in Protein Chemistry 34 167-339.)  [c.163]

What molecular architecture couples the absorption of light energy to rapid electron-transfer events, in turn coupling these e transfers to proton translocations so that ATP synthesis is possible Part of the answer to this question lies in the membrane-associated nature of the photosystems. Membrane proteins have been difficult to study due to their insolubility in the usual aqueous solvents employed in protein biochemistry. A major breakthrough occurred in 1984 when Johann Deisenhofer, Hartmut Michel, and Robert Huber reported the first X-ray crystallographic analysis of a membrane protein. To the great benefit of photosynthesis research, this protein was the reaction center from the photosynthetic purple bacterium Rhodopseudomonas viridis. This research earned these three scientists the 1984 Nobel Prize in chemistry.  [c.723]


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Organic chemistry (0) -- [ c.4 , c.54 , c.974 ]